如何在qlpreviewcontroller中自定义导航栏的颜色 [英] How to customize the color of the navigation bar in qlpreviewcontroller

问题描述

我可以在QlPreviewController控制器中自定义导航栏的颜色吗?

Can I customize the color of the navigation bar in the QlPreviewController controller?

我已经尝试关注

[[UINavigationBar appearanceWhenContainedIn: [QLPreviewController class], nil] setBarTintColor: [UIColor redColor]];

但它不起作用.

谢谢.

推荐答案

是的，如果您通过presentViewController: animated:

这是我的解决方案，请使用带有1x1图像的 setBackgroundImage:而不是 setBarTintColor:

Here's my solution, use setBackgroundImage: with 1x1 image instead of setBarTintColor:

[[UINavigationBar appearanceWhenContainedInInstancesOfClasses:@[[QLPreviewController class]]] 
    setBackgroundImage:[UIImage imageWithColor:[UIColor redColor]]
 forBarMetrics:UIBarMetricsDefault];

imageWithColor:是我的UIImage自定义类别中的一种方法，该方法返回可调整大小的1x1所需颜色的图像(在上面的示例中为红色):

And imageWithColor: is a method in my custom category of UIImage which is returning resizable 1x1 image of the desired color (red color in the example above):

+ (UIImage *)imageWithColor:(UIColor *)color {
    CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
    const CGFloat alpha = CGColorGetAlpha(color.CGColor);
    const BOOL opaque = alpha == 1;
    UIGraphicsBeginImageContextWithOptions(rect.size, opaque, 0);
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetFillColorWithColor(context, [color CGColor]);
    CGContextFillRect(context, rect);

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return image;
}

我还建议使用iOS版本检查将其包装起来，例如:

I also suggest to wrap this with iOS version check like:

if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"11.0")) {
[[UINavigationBar appearance... 
setBackgroundImage:[UIImage imageWithColor:...]
     forBarMetrics:UIBarMetricsDefault];
    }

SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO的来源:

#define SYSTEM_VERSION_EQUAL_TO(v)                  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedSame)
#define SYSTEM_VERSION_GREATER_THAN(v)              ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedDescending)
#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v)  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)
#define SYSTEM_VERSION_LESS_THAN(v)                 ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedAscending)
#define SYSTEM_VERSION_LESS_THAN_OR_EQUAL_TO(v)     ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedDescending)

这篇关于如何在qlpreviewcontroller中自定义导航栏的颜色的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！